The present invention relates to a container coupling device and, more particularly, to a container coupling device including a fully automatic latching lock providing consistent and repeatable release force characteristics.
As will be recognized by those skilled in the art, freight containers are commonly used for transporting cargo by ship and/or rail. These freight containers are generally rectangular and are dimensioned within standardized ranges used throughout the shipping industry. The containers generally include rigid corner castings of standardized size which allow the containers to be vertically and/or horizontally stacked, and thereafter locked to one another. More particularly, the corner castings include elongated or circular openings dimensioned and configured to accept locking devices, e.g., manually operated coupling devices, which allow adjacent corner castings of adjacent containers to be positively locked to one another.
Manually operated coupling devices are well known in the art. Certain known manually operated devices are disclosed in U.S. Pat. Nos. 4,212,251, 4,082,052, and 3,894,493. As will be appreciated by those skilled in the art, these coupling devices are operable between a first position wherein the device is oriented to allow coupling of adjacent corner castings, and a second position wherein the device is oriented to positively lock the adjacent corner castings to one another. In many such devices, the device includes a manually operated lever which is used to move the locking element of the coupling device between a first unlocked position and a second locked position.
In certain applications, it is not convenient and/or desirable to use manually operated coupling devices. For example, when transporting freight containers by rail, the industry often utilizes coupling devices having at least one fully automatic latching lock. Typically, the coupling devices are secured to the corner castings on the underside of a container prior to the container being moved onto the rail car. The coupling devices are oriented such that the automatic latching lock of each device is outwardly directed and thus ready to be coupled to a previously-loaded container. The automatic latching lock thus allows the container to be stacked and secured to an underlying container simply by landing the upper container onto the lower container. Similarly, the automatic latching lock allows the upper container to be uncoupled from the lower container simply through lifting of the upper container.
One common drawback associated with prior art coupling devices having automatic latching locks is repeatability of release loading. More specifically, the vertical force necessary to actuate the automatic latching lock and thus release the upper freight container from the lower freight container must be within an accepted range, and should be repeatable over time and with respect to various containers. As will be appreciated by those skilled in the art, coupling devices themselves are subjected to severe wear through handling and/or exposure to environmental factors. Corner castings of freight containers may also experience wear and/or damage. Together, these factors have made it difficult in the past to provide automatic latching locks, particularly for use in the rail industry, which consistently provide adequate securing forces.
Another potential concern when utilizing coupling devices having automatic latching locks on stacked containers concerns toppling loads, i.e., moments which cause the container to tend to topple from its stacked relationship commonly referred to as xe2x80x9crolling moments.xe2x80x9d This can be caused by the rolling action of a ship, through the application of wind forces, or by the derailment of a rail car. Under such conditions, the rolling moment experienced by the stacked cargo container could exceed the normal release force of the automatic latching lock of the coupling device thus allowing the stacked container to decouple from the underlying container and/or structure.
There is therefore a need in the art for a coupling device including at least one automatic latching lock which allows stacking of and securement of cargo containers without manual intervention. The coupling device preferably exhibits consistent and repeatable release force characteristics. Finally, the coupling device preferably resists rolling moments at onset, while still utilizing a fully automatic latching lock.
The present invention, which addresses the needs of the prior art, relates to a coupling device for cooperation with a corner casting of a freight container. The corner casting includes an interior latch-engaging surface. The coupling device includes a body having a base with first and second surfaces. The coupling device further includes an automatic latching lock extending from the first surface of the base and being sized and located for securement to the corner casting of the freight container. The automatic latching lock includes a first support shoulder and a latch assembly. The latch assembly is movably coupled to the support shoulder to allow coupling to and decoupling from the corner casting and is biased to an engagement position. The latch assembly includes a latch having a spring-receiving cavity. Finally, the coupling device includes a spring positioned within the cavity having first and second ends. The first end is supported by the latch, while the second end is surrounded by the cavity and positionally fixed with respect to the base.
The present invention further relates to a coupling device for cooperation with a corner casting of a freight container. The coupling device includes a body having a base with first and second surfaces. The coupling device further includes an automatic latching lock extending from the first surface of the base and being sized and located for securement to the corner casting of the freight container. The automatic latching lock includes a first support shoulder and a latch assembly. The latch assembly is movably coupled to the support shoulder to allow coupling to and decoupling from the corner casting and is biased to an engagement position. The latch assembly is movable in a first direction to allow coupling of the automatic latching lock to the corner casting and is movable in a second direction to allow decoupling of the automatic latching lock from the corner casting, the first direction being different from the second direction.
The present invention further relates to a coupling device for cooperation with a corner casting of a freight container. The coupling device includes a body having a base with first and second surfaces. The coupling device further includes an automatic latching lock extending from the first surface of the base and being sized and located for securement to the corner casting of the freight container. The automatic latching lock includes a latch assembly. The latch assembly is movably coupled to the base to allow coupling to and decoupling from the corner casting and is biased to an engagement position. The latch assembly includes a latch having a tail. The tail includes an upper contact surface located substantially flush with the first surface of the base when the latch is in the engagement position whereby the corner casting presses against both the first surface of the base and the contact surface of the tail when the automatic latching lock is coupled to the corner casting thus urging the latch to the engagement position.
The present invention further relates to a coupling device for coupling a corner casting of a first freight container to a corner casting of a second freight container. The coupling device includes a body having a base. The base has a first surface and a second surface. The coupling device further includes an automatic latching lock for coupling with the corner casting of the first freight container. The automatic latching lock is provided on the first surface of the base. The coupling device further includes a manual twisting lock for coupling with the corner casting of the second freight container. The manual twisting lock is provided on the second surface of the base. The manual twisting lock includes a neck extending from and connected at one end to the second surface of the base. The manual twisting lock further includes a locking element connected to the other end of the neck. The neck includes a pair of opposing protrusions. The manual twisting lock further includes a pair of opposing collar elements each having an interior wall surface. The collar elements surround the neck and are arranged as to allow relative expansion therebetween via interaction between the protrusions and the interior wall surfaces of the collar elements. The interior wall surfaces of the collar elements further include as least one pair of opposing detents sized to receive the protrusions for releasably fixing the collar elements at a predetermined rotational orientation.
The present invention further relates to a coupling device for cooperation with a corner casting of a freight container. The corner casting includes an interior latch-engaging surface. The coupling device includes a body having a base with first and second surfaces. The coupling device further includes an automatic latching lock extending from the first surface of the base and being sized and located for securement to the corner casting of the freight container. The automatic latching lock includes a first support shoulder and a latch assembly. The latch assembly is movably coupled to the support shoulder to allow coupling to and decoupling from the corner casting. Finally, the latch assembly includes a wheel rotatable with respect to the first support shoulder.
Finally, the present invention relates to a method of stacking a first freight container onto a second freight container. The method includes the step of providing a first rectangular freight container having a length and a width and an upper surface. The first freight container has first, second, third and fourth corner castings located along the upper surface. The first and second corner castings are positioned at one end of the freight container along the width. The third and fourth corner castings are positioned at the other end of the freight container along the width. The method includes the further step of providing a second rectangular freight container having a length and a width and a lower surface. The second freight container has first, second, third and fourth corner castings located along the lower surface. The first and second corner castings are positioned at one end of the freight container along the width. The third and fourth corner castings are positioned at the other end of the freight container along the width. The method includes the further step of providing first, second, third and fourth coupling devices. Each of the coupling devices includes a body having a base with first and second surfaces. Each of the coupling devices further includes an automatic latching lock associated with the first surface. The automatic latching lock includes a landing cone having a positive stop. The landing cone defines a roll-limiting direction. Each of the coupling devices further includes a manual twisting lock associated with the second surface. The method includes the further step of securing the manual twisting locks of the first and second coupling devices to the first and second corner castings of the second container such that each of the landing cones is oriented in a first direction. The method includes the further step of securing the manual twisting locks of the third and fourth coupling devices to the third and fourth corner castings of the second container such that each of the landing cones is oriented in a second direction, the first and second directions being oriented 180xc2x0 apart from one another. Finally, the method includes the step of landing the second freight container on the first freight container such that the automatic latching locks of the first, second, third and fourth coupling devices engage the first, second, third and fourth corner castings of the first freight container, respectively, whereby the first and second coupling devices limit rolling of the second freight container in a first direction and the third and fourth coupling devices limit rolling of the second freight container in a second direction.
As a result, the present invention provides a coupling device including at least one automatic latching lock which allows stacking of and securement of cargo containers without manual intervention. The automatic latching lock of the coupling device exhibits consistent and repeatable release force characteristics over time despite wear to the device and/or corner casting. Finally, the coupling device of the present invention is provided with a positive stop which resists rolling of stacked containers at onset, but nonetheless utilizes a fully automatic latching lock which allows coupling and decoupling of adjacent cargo containers without manual intervention.